Aven Tactician

Bolster is the design idea here, and the mechanic does something more pointed than a generic pump: it steers the counter toward whichever body on your board is most fragile rather than wherever you might prefer it, shoring up a weak point instead of piling onto a threat that is already ahead. Note that bolster chooses rather than targets, which lets it reinforce a creature with hexproof or shroud that a targeted pump could not touch. That constraint is the card's whole character. It does not snowball; it patches. Most often the trigger turns a one-toughness body into something that survives a single point of removal or a small block, and if the flyer itself is the frailest thing you control, it grows into a 3/4 with evasion. Because bolster places a permanent +1/+1 counter rather than a temporary boost, the upgrade survives end of turn and the rest of combat, which a one-shot pump spell does not. It also feeds the counters-matter strand of white go-wide design: a body that quietly adds a counter to the battlefield without spending a card or mana to do it. Plain and serviceable by intent, a common-rarity creature built to give a wide white board one more durable evasive threat and a small automatic trigger, slotting into the kind of token-and-counters builds that reward incremental reinforcement over a single big swing.